Skip to main content
This website uses cookies. By continuing to use this website you are agreeing to our use of cookies as described in our privacy policy.
Peter Mantas Ottawa Lawyer

Peter N. Mantas

Partner | Leader, Procurement Fasken
In an increasingly complex business world, the risk of running afoul of the law, both at home and abroad, cannot be underestimated.
Jurisdiction Ontario, 1994 | New York, 1993
Office(s) Ottawa, Toronto

Peter Mantas is the head of the Ottawa litigation group, co-leader of the firm’s White Collar Defence and Investigations group, and leader of the firm’s Procurement group.

In his practice, Peter has particular expertise in matters involving government, media, emerging technologies, mining, Indigenous affairs, transportation, competition, national security and trade. His experience covers corporate/commercial, administrative and criminal cases, and includes investigations, negotiations, mediation, arbitration, jury trials and cross border disputes.

Clients appreciate Peter’s strategic advice, careful preparation and tough but reasonable approach. Frequently retained to represent clients in sensitive, high-profile matters, he is valued for his understanding of reputational risk, media relations and crisis management. He is an avid user and proponent of technology in the litigation process in order to reduce costs and achieve better results, and has considerable experience in cases involving a large and complex documentary record.

An experienced litigation lawyer, and member of the Bars of Ontario and New York, Peter has acted in some of the most prominent cases in the country. He has appeared before numerous judicial bodies and tribunals including the Supreme Court of Canada, the superior courts of Ontario, numerous provincial and territorial courts across Canada, the Federal Court of Canada, the Canadian International Trade Tribunal, and arbitration panels.

On the global stage, Peter is frequently retained to represent clients in international arbitration and court proceedings. He has appeared as legal counsel in matters in London and New York, and acted as special counsel in various jurisdictions in Africa. He has also appeared as an expert witness in proceedings in France. In addition, Peter is a contributor to the World Bank’s report on contracting with government in Canada.  He is a frequent advisor on international trade matters, particularly involving Canada and Europe.

Peter’s expertise has been recognized by Chambers, Benchmark Litigation, Legal 500 and Best Lawyers in Canada. He has been nominated in Canadian Lawyer magazine as one of the 25 most influential lawyers in Canada. In 2020 he was invited to become a Fellow of the Litigation Counsel of America.

  • Recognized in Public Procurement Law in Ottawa, The Best Lawyers in Canada 2020 to 2021
  • Recognized in Ontario as a "Litigation Star" in Defamation, General Commercial and Media and Entertainment, Benchmark Litigation Canada 2018 to 2020
  • Recognized nationwide in Public Procurement, Chambers Canada 2016 to 2020
Date Client


  • LLB University of Ottawa
  • BA, Trinity College University of Toronto

Community involvement

Memberships & Affiliations

  • Member of the Executive 2012-17 (Co-Chair, 2015-16) Class Actions Section, Ontario Bar Association
  • Member, Canadian Bar Association
  • Member, American Bar Association
  • Member, Country of Carleton Law Association
  • Fellow, Litigation Counsel of America
Article Commentary: Anti-corruption rules watered down for US miners The Northern Miner
Article President Trump and Congress Water Down Anti-Corruption Rules for U.S. Mining Companies White Collar Post
Article CASL 2017: The Sleeping Giant Awakens Capital Perspectives
Speaker Putting CETA to Work for Canadian Business Toronto Region Board of Trade location location Toronto, ON
Panelist White Collar Crime: Prosecution and Enforcement Matters Eighth Annual London White Collar Crime Institute location location LN, United Kingdom
Speaker Doing Business with Blacklisted Companies Toronto Symposium (9th Edition) location location Toronto, ON


    Receive email updates from our team